Electronic component manufacturing method and electrode structure

Abstract

It is an object of the present invention to provide an electronic component manufacturing method, capable of suppressing reduction in a trench opening and suppressing diffusion of a metal film embedded in a trench. An embodiment of the present invention is an electronic component manufacturing method, including the steps of: forming a first electrode constituting layer (e.g., a TiAl film) in a recess (e.g., a trench) formed in a workpiece; forming an ultrathin barrier layer (e.g., a TiAlN film) by forming a nitride layer by plasma-nitriding a surface of the first electrode constituting layer; and forming a second electrode constituting layer (e.g., an Al wiring layer) on the ultrathin barrier layer.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]This application is a continuation application of International Application No. PCT / JP2012 / 006104, filed Sep. 25, 2012, which claims the benefit of Japanese Patent Application No. 2012-012240, filed Jan. 24, 2012. The contents of the aforementioned applications are incorporated herein by reference in their entireties.TECHNICAL FIELD[0002]The present invention relates to an electronic component manufacturing method and an electrode structure, and more particularly relates to an electronic component manufacturing method and an electrode structure, the method including a step of embedding a metal film in a recess formed in a workpiece.BACKGROUND ART[0003]For conventional semiconductor integrated circuits, a gate-first method has been used in which a gate insulating film and a gate electrode are formed first on a wafer surface, and then processing by etching is performed. In recent years, thinning of a gate insulating film in a MOSFET has be...

AI Technical Summary

Benefits of technology

[0015]Meanwhile, in the method described in Patent Document 3, a first barrier layer and a second barrier layer need to be formed so that agglomeration of a low-melting-point metal deposited at high temperature can be prevented or reduced and a recess can be filled with the low-melting-point metal with high throwing power. This leads to a problem that the barrier layers are increased in thickness. Meanwhile, the method described in Patent Document 4 enables embedding of Al without reducing the opening diameter even in a minute trench having an opening diameter of 22 mm or less. However, in the method described in Patent Document 4, the Al layer needs to be embedded under a temperature condition that allows the layer to flow. In the case of a minute trench having an opening diameter of 15 nm or less, there is a concern that unevenness on the surface of the Al film may affect the performance of electronic components.

[0016]The present invention was made in consideration of the foregoing conventional problems. It is an object of the present invention to provide an electronic component manufacturing method, capable of solving the problems described above, suppressing reduction in a trench opening, and suppressing diffusion of a metal film embedded in a trench.

[0019]According to the present invention, metal can be embedded even in a minute trench having an opening diameter of 15 nm or less while suppressing reduction in opening diameter by forming a first electrode constituting layer (e.g., a TiAl film) formed on a workplace (first step) with a recess (e.g., a trench) formed therein, forming an ultrathin barrier layer (e.g., a TiAlN film) by forming a nitride layer by plasma-nitriding a surface of the first electrode constituting layer (e.g., the TiAl film) (second step), and forming a second electrode constituting layer (e.g., on Al wiring layer) on the ultrathin barrier layer (e.g., the TiAlN film) (third step). Therefore, even when the electronic component manufacturing method including the step of embedding a metal film according to the present invention is applied to a method for manufacturing a wiring, a metal film can be embedded while suppressing reduction in an opening diameter of a minute trench having an opening diameter of 15 nm or less. Moreover, in an electrode structure formed by the electronic component manufacturing method according to the present invention, a metal wiring layer is formed flat without unevenness on an ultrathin barrier layer (e.g., a TiAlN film) while suppressing reduction in an opening diameter of a minute trench having an opening diameter of 15 nm or less. Thus, an effect is achieved that embedding performance can be enhanced and the yield of a gate-last device can be improved.

Problems solved by technology

However, the above techniques have the following problems, respectively.

The method involving sputtering at a high pressure of 1 Torr or more described in Patent Document 1 has a problem that, even though deposition on the sidewall of the trench can be performed, the trench opening is narrowed when the trench opening is reduced to 15 nm or less.

Moreover, the Al embedding method described in Patent Document 2 has a problem that the Ti and TiN laminated barrier film needs to be thickly deposited to suppress Al diffusion.

There is also a problem that, since the Seed-Al layer is further formed on the Ti and TiN laminated barrier film to facilitate Al migration, the trench opening is narrowed.

This leads to a problem that the barrier layers are increased in thickness.

In the case of a minute trench having an opening diameter of 15 nm or less, there is a concern that unevenness on the surface of the Al film may affect the performance of electronic components.

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